Device for feeding thread to needles of a knitting machine

Abstract

A device (1) for feeding thread to the needles (N) of a knitting machine, the device comprising a body (2) destined to be associated to a needle-bearing organ of the knitting machine, and provided with at least a housing seating (3) configured such as to movably house the thread guide means (4) in the body. The device is provided with thread guide means (4), movably housed in the housing seating (3) and comprising a first lever (5), a thread guide (6) and a second lever (10). The first lever is rotatably mounted to the body (2) such as to be able to rotate about a first rotation axis (X); the thread guide is rotatably mounted to the first lever (5) so as to be able to rotate, with respect to the first lever, about a second rotation axis (Y). The thread guide extends longitudinally between a rear end (7) and a front end (8); the front end (8) extends and emerges from the seating (3) in the direction of the needle-bearing organ, and defines at least a passage (61) for a thread to be dispensed to the needles (N) of the needle-bearing organ; the thread guide is further provided with a guide portion (9). The second lever (10) is rotatably mounted to the body (2) so as to be rotatable about a third rotation axis (Z) and extends between an activating end (11) and a guide end (12), to which the guide portion (9) of the thread guide is maintained slidably in contact. The thread guide means further comprise activating means which controlledly move the first (5) and the second lever (10) so as to position the thread guide (6) in a plurality of operating positions with respect to the needle-bearing organ of the knitting machine.

The invention claimed is: 
     
       1. A device ( 1 ) for feeding thread to the needles (N) of a knitting machine, the device comprising:
 a body ( 2 ) of the device configured to be mounted to a knitting machine, at a needle-bearing organ of the knitting machine, 
 thread guide members ( 4 ), movably housed at least partially in said body ( 2 ), wherein the thread guide members comprise: 
 a first lever ( 5 ) rotatably mounted to said body ( 2 ) of the device so as to be able to rotate about a first rotation axis (X); 
 a thread guide ( 6 ) rotatably mounted to said first lever ( 5 ) so as to be able to rotate, with respect to said first lever, about a second rotation axis (Y), said thread guide ( 6 ) having an elongate shape and extending longitudinally between a rear end ( 7 ) and a front end ( 8 ), the front end ( 8 ) projecting and emerging from said body ( 2 ) in a direction of said needle-bearing organ and defining at least a passage ( 61 ) for a thread to be dispensed to the needles (N) of said needle-bearing organ, said thread guide being provided with a guide portion ( 9 ) interposed between the rear end ( 7 ) and the front end ( 8 ); 
 a second lever ( 10 ) rotatably mounted to said body ( 2 ) of the device so as to be able to rotate about a third rotation axis (Z), the second lever longitudinally extending between an activating end ( 11 ) and a guide end ( 12 ), said guide portion ( 9 ) of the thread guide ( 6 ) being configured to stay slidably in contact with said guide end of the second lever; 
 activating members ( 13 ) positioned at least partially in said body ( 2 ) and configured and predisposed for controlledly moving at least said first lever ( 5 ) and said second lever ( 10 ) so as to position the thread guide ( 6 ) in a plurality of operating positions with respect to the body and with respect to the needle-bearing organ of the knitting machine, 
 wherein the thread guide members ( 4 ) are characterised in that the first lever ( 5 ), the second lever ( 10 ) and the thread guide ( 6 ) together realise a four-bar linked kinematic structure configured so as to selectively position the front end ( 8 ) of the thread guide ( 6 ) in the plurality of operating positions, and wherein the four-bar linked kinematic structure is kinematically defined by the first rotation axis (X), the second rotation axis (Y), a direct contact point between the guide portion ( 9 ) of the thread guide ( 6 ) and the guide end ( 12 ) of the second lever ( 10 ), and the third rotation axis (Z). 
 
     
     
       2. The device ( 1 ) of  claim 1 , wherein the activating members ( 13 ) comprise a first actuator ( 14 ) activatable on the first lever ( 5 ) to determine a rotation thereof about the first rotation axis (X) of a first regulatably-variable angle between an advanced position and a retracted position, to which correspond respectively a displacement of the front end ( 8 ) of the thread guide distancingly from the needle-bearing organ and a displacement of the front end ( 8 ) of the thread guide nearingly to the needle-bearing organ, the displacements occurring in a range of motion and a trajectory being a function of the shape of the guide portion of the thread guide; and wherein the activating members ( 13 ) comprise a second actuator ( 15 ) activatable on the second lever ( 10 ) so as to determine a rotation thereof, about the third rotation axis (Z) of a second regulatably-variable angle, between a first position and a second position, to which correspond respectively a displacement of the front end ( 8 ) of the thread guide ( 6 ) in a rising direction with respect to the needle-bearing organ, up to a first vertical height ( 101 ), and a displacement of the front end ( 8 ) of the thread guide ( 6 ) in a lowering direction with respect to the needle-bearing organ, to a second vertical height ( 102 ) lower than the first vertical height. 
     
     
       3. The device ( 1 ) of  claim 1 , wherein the thread guide members ( 4 ) comprise elastic members positioned at least partially in the body ( 2 ) and configured and predisposed to elastically oppose the movement imparted on the first lever ( 5 ) and on second lever ( 10 ) by the activating members ( 13 ). 
     
     
       4. The device ( 1 ) of  claim 2 , wherein the activating members comprise a third actuator ( 19 ) acting on the second lever ( 10 ) to determine a further rotation thereof, about the third rotation axis (Z) of a third regulatable angle, between the first or second position and a third position, in which to the further rotation of the second lever so as to bring itself into the third position corresponds a displacement of the front end ( 8 ) of the thread guide in a lowering direction with respect to the needle-bearing organ, up to a third vertical height ( 103 ) lower than the second vertical height ( 102 ). 
     
     
       5. The device ( 1 ) of  claim 1 , wherein the thread guide ( 6 ) is rotatably hinged to the first lever ( 5 ) at the rear end ( 7 ) of the thread guide ( 6 ) and wherein the thread guide ( 6 ) is rotatably hinged to a lower end ( 5   a ) of the first lever ( 5 ), and wherein the rear end ( 7 ) of the thread guide and the lower end ( 5   a ) of the first lever realize a cylindrical joint ( 20 ) which enables relative rotation between the thread guide and the first lever at least about the second rotation axis (Y). 
     
     
       6. The device ( 1 ) of  claim 1 , wherein the thread guide ( 6 ) exhibits a back ( 6   a ) at a thickness of the thread guide, the thickness developing perpendicularly to the longitudinal development of the thread guide and the back being in an upper position in the thread guide, and the guide portion ( 9 ) of the thread guide is defined on the back of the thread guide and comprises a portion of an upper surface of the thread guide which extends in the direction of the longitudinal development of the thread guide, and wherein the portion of upper surface defining the guide portion develops on planes that are substantially parallel to the second rotation axis of the thread guide with respect to the first lever. 
     
     
       7. The device ( 1 ) of  claim 4 , wherein the plurality of operating positions of the thread guide ( 6 ) comprises one or more of the following operating positions:
 a first operating position, obtained by activation of the first actuator ( 14 ) and deactivation of the second actuator ( 15 ), wherein the front end ( 8 ) of the thread guide is positioned in a first point (A) in which the thread guide is prepared for lowering towards the second vertical height and the third vertical height; 
 a second operating position, obtained by deactivation of the first ( 14 ) and the second actuator ( 15 ), wherein the front end of the thread guide is positioned in a second point (B) in which either the possibility of an uptake of the thread by the needles (N) of the knitting machine is excluded, or the thread, previously dispensed to the needles of the machine, is brought posteriorly of the needle head; 
 a third operating position, obtained by activation of the first ( 14 ) and the second actuator ( 15 ), in which the front end of the thread guide is positioned in a third point (C) in which all the needles (N) of the knitting machine can take up the thread; 
 a fourth operating position, obtained by deactivation of the first actuator ( 14 ) and activation of the second actuator ( 15 ), in which the front end of the thread guide is positioned in a fourth point (D) in which uptake is enabled only for the needles (N) of the knitting machine which are raised more than other needles, which other needles are raised less and therefore do not take up the thread; 
 a fifth operating position, obtained by activation of the first ( 14 ) and the third actuator ( 19 ), in which the front end of the thread guide is positioned in a fifth point (E) in which thread take-up is enabled for all the needles (N) of the knitting machine, which needles (N) are brought into working condition at the desired infeed; 
 a sixth operating position, obtained by deactivation of the first actuator ( 14 ) and activation of the third actuator ( 19 ), in which the front end of the thread guide is positioned in a sixth point (F) in which take-up of the thread is enabled only for the needles (N) of the knitting machine which are raised less, while thread take-up is disabled for the needles (N) which are raised more, as the infed thread is positioned lower than the tongue of the latter needles (N). 
 
     
     
       8. The device ( 1 ) of  claim 1 , wherein the body ( 2 ) is provided with at least a housing seating ( 3 ) and wherein the thread guide members ( 4 ) are located at least partly within the housing seating, in which the first lever ( 5 ) and the second lever ( 10 ) are rotatably mounted to the body internally of the housing seating, the front end ( 8 ) of the thread guide projects and emerges from the housing seating in the direction of the needle-bearing organ and the activating members are positioned internally of the housing seating, or wherein the body ( 2 ) comprises a plurality of the housing seatings ( 3 ), distinct from one another, each of the housing seatings being configured to movably house respective thread guide members ( 4 ) in the body, each of the respective thread guide members comprising at least a respective thread guide ( 6 ) and respective activating members ( 13 ) configured so as position the respective thread guide in a plurality of operating positions with respect to the housing seating and with respect to the needle-bearing organ of the knitting machine. 
     
     
       9. A knitting machine for knitwear or hosiery, comprising a needle-bearing organ exhibiting a plurality of flanked grooves extending substantially vertically, each groove movably housing a needle (N) mobile on command in the respective groove for the formation of fabric, and comprising a device ( 1 ) for feeding thread to the needles, the device comprising:
 a body ( 2 ) of the device configured to be mounted to a knitting machine, at a needle-bearing organ of the knitting machine, 
 thread guide members ( 4 ), movably housed at least partially in said body ( 2 ), wherein the thread guide members comprise: 
 a first lever ( 5 ) rotatably mounted to said body ( 2 ) of the device so as to be able to rotate about a first rotation axis (X); 
 a thread guide ( 6 ) rotatably mounted to said first lever ( 5 ) so as to be able to rotate, with respect to said first lever, about a second rotation axis (Y), said thread guide ( 6 ) having an elongate shape and extending longitudinally between a rear end ( 7 ) and a front end ( 8 ), the front end ( 8 ) projecting and emerging from said body ( 2 ) in a direction of said needle-bearing organ and defining at least a passage ( 61 ) for a thread to be dispensed to the needles (N) of said needle-bearing organ, said thread guide being provided with a guide portion ( 9 ) interposed between the rear end ( 7 ) and the front end ( 8 ); 
 a second lever ( 10 ) rotatably mounted to said body ( 2 ) of the device so as to be able to rotate about a third rotation axis (Z), the second lever longitudinally extending between an activating end ( 11 ) and a guide end ( 12 ), said guide portion ( 9 ) of the thread guide ( 6 ) being configured to stay slidably in contact with said guide end of the second lever; 
 activating members ( 13 ) positioned at least partially in said body ( 2 ) and configured and predisposed for controlledly moving at least said first lever ( 5 ) and said second lever ( 10 ) so as to position the thread guide ( 6 ) in a plurality of operating positions with respect to the body and with respect to the needle-bearing organ of the knitting machine, 
 
       wherein the thread guide members ( 4 ) are characterised in that the first lever ( 5 ), the second lever ( 10 ) and the thread guide ( 6 ) together realise a four-bar linked kinematic structure configured so as to selectively position the front end ( 8 ) of the thread guide ( 6 ) in the plurality of operating positions, and wherein the four-bar linked kinematic structure is kinematically defined by the first rotation axis (X), the second rotation axis (Y), a direct contact point between the guide portion ( 9 ) of the thread guide ( 6 ) and the guide end ( 12 ) of the second lever ( 10 ), and the third rotation axis (Z),
 the needle-bearing organ being mobile with respect to the device for feeding thread along a motion trajectory. 
 
     
     
       10. The device ( 1 ) of  claim 3 , wherein the elastic members comprise a first elastic element ( 17 ) having an end constrained to the body ( 2 ) and an opposite end constrained to the thread guide ( 6 ), the first elastic element ( 17 ) being configured to determine a tensioning of the thread guide ( 6 ) towards the second lever ( 10 ) and to maintain the guide portion ( 9 ) of the thread guide in contact with the guide end ( 12 ) of the second lever ( 10 ), and wherein the first elastic element ( 17 ) is configured to determine a tensioning of the thread guide ( 6 ), towards the first vertical height, so as to transmit, by the guide portion ( 9 ) of the thread guide in contact with the guide end ( 12 ) of the second lever, a thrust on the second lever ( 10 ) towards the first position thereof. 
     
     
       11. The device ( 1 ) of  claim 10 , wherein the first elastic element ( 17 ) is configured to oppose the action at least the second actuator ( 15 ), maintaining the second lever ( 10 ) in the respective first position when the second actuator does not act on the second lever, and wherein the elastic members comprise a second elastic element ( 18 ) having an end constrained to the body ( 2 ) and an opposite end constrained to the first lever ( 5 ), the second elastic element ( 18 ) being configured to determine a tensioning of the first lever ( 5 ) towards the retracted position and to oppose the action of the first actuator ( 14 ), maintaining the first lever in a retracted position when the first actuator does not act on the first lever. 
     
     
       12. The device ( 1 ) of  claim 1 , wherein the first lever and the second lever are rotatably mounted to a same point of the body ( 2 ), in which case the first rotation axis (X) and the third rotation axis (Z) coincide, and wherein the first rotation axis (X) is orientated substantially parallel to the tangent to the motion trajectory of the needle-bearing organ relatively to the body ( 2 ), and wherein the second rotation axis (Y) is substantially parallel to, and distinct from, the first rotation axis (X). 
     
     
       13. The device ( 1 ) of  claim 4 , wherein the activation of the third actuator ( 19 ) enables rotating the guide end of the second lever in a downwards direction, bringing it into the third position, and the passage of the second lever into the third position can occur both starting from the first position, and starting from the second position, when starting from the first position the third actuator moving the second lever—in a lowering direction—from the first height directly to the third vertical height, while when starting from the second position the third actuator moving the second lever—in a lowering direction—from the second height to the third vertical height. 
     
     
       14. The device ( 1 ) of  claim 1 , wherein the activating members ( 13 ) are active on the first lever ( 5 ) and on the second lever ( 10 ) and do not directly interact with the thread guide ( 6 ). 
     
     
       15. The device ( 1 ) of  claim 2 , wherein the thread guide members ( 4 ) comprise a third lever ( 30 ) rotatably mounted to the body ( 2 ) in such a way as to be able to rotate about a fourth rotation axis (W), the third lever ( 30 ) comprising an activating portion ( 31 ), which the second actuator ( 15 ) can act, and a thrust portion ( 32 ), the thrust portion being configured to interact with the activating end ( 11 ) of the second lever ( 10 ) so as to determine the rotation of the second lever about the third rotation axis (Z) between the first position and the second position. 
     
     
       16. The device ( 1 ) of  claim 5 , wherein the cylindrical joint ( 20 ) comprises a protrusion ( 21 ) having a conformation, in a perpendicular section to the second axis (Y), at least partially circular, and comprises a recess ( 22 ) complementarily-shaped to the protrusion ( 21 ) and configured to house the protrusion so as to enable rotation thereof internally of the recess, and wherein the protrusion ( 21 ) emerges from and is solidly constrained to or in a single piece with the first lever and the recess ( 22 ) is fashioned in the thread guide, or the protrusion ( 21 ) emerges from and is solidly constrained to or in a single piece with the thread guide and the recess ( 22 ) is fashioned in the first lever. 
     
     
       17. The device ( 1 ) of  claim 1 , wherein the guide end ( 12 ) of the second lever ( 10 ) comprises a bearing ( 23 ) or roller configured to enable or facilitate sliding of the guide portion ( 9 ) of the thread guide with respect to the guide end ( 12 ) of the second lever. 
     
     
       18. The device ( 1 ) of  claim 6 , wherein the guide portion ( 9 ) on the back ( 6   a ) of the thread guide is maintained pressed, with a determined force, on the guide end ( 12 ) of the second lever ( 10 ) by the first elastic element ( 17 ), which prevents detachment of the thread guide from the second lever. 
     
     
       19. The device ( 1 ) of  claim 6 , wherein the thread guide comprises a fin emerging superiorly from the thread guide and developing over a longitudinal portion of the thread guide, parallel to the longitudinal axis of the thread guide, the back of the thread guide being defined on the fin or coinciding with an upper surface of the fin, and wherein the guide portion is defined on an upper surface of the fin. 
     
     
       20. The device ( 1 ) of  claim 7 , wherein the thread guide ( 6 ) comprises a foot ( 55 ) configured to cooperate with a stop ( 57 ) of the device for halting a radial advancement of the thread guide, nearingly to the needle-bearing organ, in the motion thereof towards the fourth position (D), or towards the sixth position (F), in this way defining the respective radial distance of the front end ( 8 ) from the needle-bearing organ in the fourth position (D) or sixth position (F), the foot ( 55 ) being positioned inferiorly of the thread guide and in an intermediate position between the rear end and the front end, the foot ( 55 ) of the thread guide ( 6 ) comprising a front surface ( 56 ), configured to enter into contact with the stop ( 57 ) and to cause halting of the radial motion of the thread guide towards the needle-bearing organ, and wherein the front surface of the foot is shaped or profiled in such a way that when the foot ( 55 ) is in contact with the stop ( 57 ), a vertical movement of the thread guide determines a thrust by the stop on the front surface of the foot, the thrust causing a radial displacement of the foot and the whole thread guide according to a trajectory which is a function of the shaping or profiling of the front surface of the foot.